docs: def reqs_txt(self):
          """
          Export a requirements file in txt format.
          """
          role_lines = ""
  
          for role in sorted(self.report["roles"]):
              name = utils.normalize_role(role, self.config)
              galaxy_name = "{0}.{1}".format(self.config["scm_user"], name)
  
              version_path = os.path.join(self.roles_path, role, "VERSION")
              version = utils.get_version(version_path)
              role_lines += "{0},{1}\n".format(galaxy_name, version)
  
          if self.out_file:
              utils.string_to_file(self.out_file, role_lines)
          else:
              print role_lines